Why Hydroponic Gardenia Leaves Suddenly Turn Yellow and How to Fix It

Gardenias are easy to grow and are described as blooming year-round, evergreen in all four seasons, and richly fragrant, and as long as you pay attention to these few points, they will rebloom every year!! A newly bought gardenia has lots and lots of flower buds, so why do the leaves turn yellow after just a few days? But don't worry, today we'll reveal the real reasons gardenia leaves turn yellow, and share practical solutions!

1. Overwatering

Symptoms:

The potting soil stays wet for more than 2 days, leaves gradually turn yellow, the edges turn black and develop black spots, and flower buds drop off.

Solution:

Improve ventilation, move the plant to a balcony or windowsill, and open the windows for airflow;

Stop watering; if there are signs of rot, repot promptly, clean up the rotten roots, and replant.

2. Improper Fertilizing

Symptoms:

After fertilizing a gardenia that is in bloom, the flowers drop off, and the leaf edges dry out, curl, and turn black.

Solution:

When fertilizer burn occurs, place the pot on a slatted stool and flush it thoroughly with plenty of water to wash out the fertilizer; solid fertilizer can be dug out.

Fertilizing should be done before the flower buds show color; use monopotassium phosphate diluted with water at a 1:1000 ratio to spray the leaves (avoiding the flower buds), and at a 1:2000 ratio for root watering; it should not be too concentrated.

3. Iron-Deficiency Yellow Leaves

Symptoms:

Highly alkaline water or soil alkalization causes yellow leaves; in the early stage the leaf veins stay dark, and later the veins also turn yellow.

Solution:

Water with a ferrous sulfate solution once a month, using a 1:2000 ratio for root watering; pause use during the flowering period. Treat the yellow leaves first, then fertilize; once the leaves turn green again, use other fertilizers.

4. Normal Metabolism

Symptoms:

Commercially sold gardenias are mostly treated with greenhouse fertilizers and hormones; after arriving home they lack nutrients, and yellowing starts from the old leaves.

Solution:

Remove the small flower buds and keep 3-5 large flower buds;

Remove aging yellow leaves promptly; in severe cases, remove all flower buds and let the plant grow new leaves again.

Gardenia care tips:

1. Light: a short-day plant, grow it indoors in bright conditions.

2. Water: follow the principle of watering when dry and letting it dry between waterings, keeping the potting soil moist; gardenias like moisture, and April to September is the growing season. During the growing season, be sure to keep the potting soil moist; in the evening you can also sprinkle water on the leaves to keep them humid, but water in moderation; in winter the water requirement is lower, so do not water too much.

3. Fertilizing: follow the principle of light, frequent feeding; generally a nitrogen-phosphorus-potassium mixed nutrient solution is fine. During the growing season, fertilize once every half month; in spring and autumn, once a month; in winter, low temperatures send it into dormancy and no fertilizer is needed, so stop fertilizing in winter.

4. Misting: when the indoor temperature exceeds 25 degrees, you can mist the plant leaves appropriately; below 15 degrees, stop misting. Never mist in direct sunlight, and do not let water collect on the leaves~

   5. Soil

   Gardenias are not demanding about soil; the only requirement is that they grow in slightly acidic soil, ideally with a pH between 5 and 6.5. You can simply choose a ready-made potting mix available online, which is both loose and breathable and rich in nutrients, and saves trouble; an ordinary clay pot will do.